Streptomyces. Saccharomycopisis. Spirillum. Saccharomyces. Spherotilus. Rhodotorula. Sarcina. Rhodosporidium. Psedomonas. Penicillium. Peptococcus.
Bioremediation of Oil Spills
Alison Hawkins
Outline Introduction Regulations Inland vs. Ocean Methods Bioaugmentation Biostimulation Case Studies Advancements
According to the EPA, “oil releases threaten public health and safety by contaminating drinking water, causing fire and explosion hazards, diminishing air and water quality, compromising agriculture, destroying recreational areas, wasting nonrenewable resources, and costing the economy millions of dollars.”
Introduction • Occur frequently throughout the world • Require quick action Regulations • EPA • Coast Guard
Inland vs. Ocean Spills Differences: Who is in charge of cleaning it up Who causes the spills Attention Size of spill Similarities: Threat to populations Require quick action
Methods Physical Chemical Biological
Bioremediation Bioremediation: the use of microorganisms to decompose pollutants into simpler compounds Degradation: the process of microbes breaking substances down into water, CO2, and other compounds Prime goal Two types Secondary treatment tool
Bacteria
Bioaugmentation Bioaugmentation: addition of microbes to supplement the current population to degrade oil and other hydrocarbons
Table from Gordon
Fungi
Achromobbacter
Allesheria
Acinetobacter
Aspergillus
Actinomyces
Aureobasidium
Aeromonas
Botrytis
Alcaligenes
Candida
Arthrobacter
Cephaiosporium
Bacillus
Cladosporium
Beneckea
Cunninghamella
Brevebacterium
Debaromyces
Coryneforms
Fusarium
Erwinia
Gonytrichum
Flavobacterium
Hansenula
Klebsiella
Helminthosporium
Lactobacillus
Mucor
Leucothrix
Oidiodendrum
Moraxella
Paecylomyces
Nocardia
Phialophora
Peptococcus
Penicillium
Psedomonas
Rhodosporidium
Sarcina
Rhodotorula
Spherotilus
Saccharomyces
Spirillum
Saccharomycopisis
Streptomyces
Scopulariopsis
Vibrio
Sporobolomyces
Xanthomyces
Torulopsis Trichoderma Trichosporon
Bioaugmentation Unable to degrade certain contaminants Polluted environments, 10% of resident microbe population are degraders Other requirements must be met Microbes have a peak concentration Microbes must compete to survive Genetically altered microbes
Biostimulation Biostimulation: addition of nutrients to aid in the growth of the indigenous microbe population Major nutrients: carbon, nitrogen, phosphorous, oxygen, and water Main concerns are oxygen supply and temperature Nutrients must be available and in contact with microbes
Biostimulation 1 g hydrocarbon requires 150mg N and 30mg P C:N:P = 100:5:1 Fertilizer Rate of release Washout effect Type of nutrients
Table from Zhu et al
Advantages • Less expensive • Natural process • Not disruptive to surrounding ecosystems • Does not require moving oil to another location • Continues to improve conditions
Disadvantages • Bioaugmentation not very effective • Success depends on proper nutrients and environmental conditions • Takes time to evaluate site • Takes time to see results
Exxon Valdez • Oil tanker received 1.26 million barrels of
oil (54 million gallons) in Alaska • Bottomed out on rocks of the Bligh Reef in Prince William Sound • 8 of the 11 cargo holds on the ship broke and within 5 hours, 11 million gallons of oil had spilled • 80% of oil remained on the ship
Figure from Gordon
Exxon Valdez • Needed to remove remaining oil and
cleanup the spilled oil • Had to consider surrounding ecosystems • Many methods tried • 3 years later, the Coast Guard discontinued the effort • EPA asked if they could use experimental technology
Exxon Valdez • Analysis of different test plots • Used biostimulation • Oleophoric fertilizer – 10,000 fold increase of oil-eating microbes
• Within two weeks, saw a change in
amount of oil on the rocks and beaches • Tests showed this was due to fertilizer • Increase test area
Ashland Oil Spill • Four million-gallon storage tank collapsed • Oil flowed from the tank, across a parking lot, through a storm sewer to the Mongahela River into the Ohio River
Figure from EPA
Ashland Oil Spill • Half the size of the Exxon Valdez spill • Larger impact on populations • Killed thousands of waterfowl and fish, closed 15 municipal drinking water intakes, and disrupted drinking water supply for 2.7 million people. • Mechanical methods were used • Only 20% of oil was recovered
Spill Effects • Sparked public awareness • More stringent regulations and laws enacted – Oil Pollution Act of 1990 • Helped encourage the use and advancement of bioremediation
Advancements Information gained includes: • Determining the effectiveness of bioremediation agents • Statistical proof that bioremediation enhances disappearance rate of crude oil • Minimum N concentration necessary Difficult to perform controlled experiments
Conclusion • Oil spills can happen anywhere • Require quick reaction time • Various methods available • Bioremediation is an emerging process
that needs to be analyzed farther to see the true effectiveness of the process
References • EPA Office of Emergency and Remedial Response. Ch 8 • EPA Website. (2006) http://www.epa.gov/oilspill/index.htm • Gordon, Ray. (1994) “Bioremediation and its Application to Exxon Valdez Oil Spill in • • •
Alaska.” Michel, J., S. Christopherson, and F. Whipple. (1994) Mechanical Protection Guidelines. Columbia, South Carolina Nichols, William J. The United States Environmental Protection Agency: National Oil
Hazardous Substances Pollution Contingency Plan, Subpart J Product Schedule(40 CFR 300.900). Office of Technology Assessment (OTA), U.S. Congress. (1991) Bioremediation for Marine Oil Spills- Background Paper, OTA-BP-O-70 (Washington, DC: U.S.
Government Printing Office).
• Understanding Oil Spills and Oil Spill Response. (1990) US EPA, Office of Emergency • •
and Remedial Response. Venosa, Albert D. “NRT Fact Sheet: Bioremediation in Oil Spill Response.” EPA, Cincinatti, OH. Zhu, X., A. Venosa, M. Suidan, and K. Lee. (2001) Guidelines for the Bioremediation of Marine Shorelines and Freshwater Wetlands. U.S. EPA, Cincinatti, Ohio.
Questions?
